public List <HealthFacility> AssociateWith(List <HealthFacility> facilities) { foreach (var facility in facilities) { var pos = Locations.BinarySearch(new Tuple <string, Tuple <double, double> >(facility.Name.Trim(), null), Placer); if (pos < 0) { continue; } var loc = Locations[pos]; facility.Latitude = loc.Item2.Item1; facility.Longitude = loc.Item2.Item2; } return(facilities); }